Aggregate composition containing synthetic thermoplastic resin pellets or fragments

ABSTRACT

1. IN A COMPOSITION USEFUL AS A PAVING MATERIAL COMPRISING IN ADMIXTURE AGGREGATE AND A BINDER SELECTED FROM THE GROUP CONSISTING OF A BITUMINOUS MATERIAL AND APETROLEUM RESIN, THE IMPROVEMENT WHEREIN FROM 3-75% BY WEIGHT OF SAID AGGREGATE IS REPLACED WITH SOLID SYNTHETIC THERMOPLASTIC RESIN PARTICLES SELECTED FROM THE GROUP CONSISTING OF VINCYL CHLORIDE RESINS, POLYETHYLENE, POLYPROPYL ENE, POLYSTYRENE, ACRYLONITRILE-BUTADIENE-STYRENE AND METHACRYLIC RESINS IN THE FORM OF PELLETS OR FRAGMENTS HAVING A MAXIMUM LENGTHWISE DIAMETER OF ABOUT 1-220 MM. IN SAID ADMIXTURE.

United States Patent O US. Cl. 260-285 R 7 Claims ABSTRACT OF THEDISCLOSURE An improved aggregate or road paving composition comprisingan admixture of aggregate and a binder selected from bituminous materialand petroleum resins wherein from 3 to 75% by weight of the aggregate isreplaced with synthetic resin particles.

This application is a continuation application of application Ser. No.168,722, filed Aug. 3, 1971, now

abandoned.

BACKGROUND OF THE INVENTION This invention relates to an improvedcomposition comprising aggregate, synthetic resin particles and binders.More particularly, this invention relates to improved aggregatecompositions, wherein a portion of the aggregate in the composition isreplaced by thermoplastic synthetic resin particles.

DESCRIPTION OF THE PRIOR ART Generally, road paving compositions areprepared by one of two methods. The first method, known as theheatmixing method, comprises heating a mixture of crushed stone andsand, which are premeasured to obtain a prescribed particulatedistribution, to remove the moisture and to facilitate the mixing of thecrushed stone and sand with a binder, such as bituminous material; thecrushed stone and sand are then charged to a mixer and kneaded for atleast 5 seconds with a filler; and finally the binder and rubber latex,if any, are charged to the mixer with mixing continuing until the binderhas coated all of the aggregate. Usually, the paving composition isobtained by mixing for 40 to 50 seconds at a temperature of about 150 C.to about 160 C. This paving composition is transported in its heatedstate and spread over the rod surface as the base or sub-base, with anasphalt finisher and subsequently rolled with a road roller and tireroller.

The second method, known as the permeation method, comprises uniformlyspraying a pre-determined amount of binder onto the aggregate so thatthe binder permeates the interstices between the aggregate and creates astable layer by the engagement of the aggregate and the binding force ofthe binder. This method includes both the heating of the binder beforespraying and the spraying of the binder at ambient temperature withoutheating.

The aggregates used with the binder must adhere well to the binder, andthe grade and particle size of the aggregates greatly affect theperformance of the resulting pavement. A mixture of crushed stone,crushed round stones, gravel, slag, sand and filler is usually used asthe aggregate. Crushed stone is obtained by crushing rocks, and When ithas just been crushed by a crusher and is in its as-crushed state, it iscalled the crusher run. Crushed round stones are those obtained bycrushing either round stones or gravel and have a particle size suchthat the stones do not pass through a 5 mm. sieve, at least 40% byweight of these particles having at least one broken surface. Gravel isclassified by its source such as river, bank run, mire or seashore, andgravels which include sand are called run-of-the-mill gravel. Slag isformed by crushing air-cooled blast furnace slag, and has a uniformgrade and density. There are two types of sand, natural and crushedsand. Natural sand is classified in accordance with its source, whilecrushed sand is made by crushing rock and round stones. The sand must beclean and have suitable hardness, durability and particle size for itsintended use and must not contain a deleterious amount of trash, mud,organic matter, etc. Filler is a finely divided powder of limestone,slaked lime, portland cement or igneous rock and must not contain morethan 1.0% mositure.

The binder is the material which binds the aggregate together and, uponhardening, must be capable of maintaining the strength of the pavementin cooperation with the aggregate. Bituminous materials such as straightasphalt, asphalt emulsion, cutback asphalt and tar, as well as petroleumresins are generally used as the binder.

When binder coated aggregate contacts water, the binder tends to bestripped from the surface of the aggregate. Further, the adhesivenessbetween the aggregate and the binder depends on the properties of theaggregate as Well as the properties of the binder. Therefore, inpreparing the paving material, the selection of aggregate components anddetermination of their composition and the choice of the binder and theoptimum amount in which it is to be incorporated are of utmostimportance.

Also, in recent years, the widespread use of synthetic plastics hascreated a disposal problem since these plastics are not biodegradableand maintain their composition indefinitely. The obvious pollutionproblem created by these plastics could be alleviated if some economicaluse for these waste plastics could be found.

It is, therefore, within the above environment and background that thecomposition of the present invention was developed.

BRIEF SUMMARY AND OBJECTS OF THE PRESENT INVENTION The improvedaggregate or surfacing composition of the present invention comprises amixture of aggregate and a binder selected from bituminous materials orpetroleum resins wherein from 3 to by weight of the aggregate isreplaced with particles of a synthetic thermoplastic resin.

It is, therefore, the primary object of the present invention to providean improved aggregate paving composition.

It is another object of the present invention to provide an aggregatecomposition which includes from 3 to 75 by weight of particles of athermoplastic resin.

It is still a further object of the present invention to provide aneffective use for scrap plastic articles.

It is still a further object of the present invention to provide asimple means for producing colored paving surfaces.

Still further objects and advantages of the composition of the presentinvention will become more apparent from the following detaileddescription thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS It has now been foundin accordance with the composition of the present invention that when aportion of the aggregate is replaced with particles of synthetic resin,these particles being either pellets produced by molding a syntheticresin or fragments produced by crushing shaped articles of syntheticresins, the synthetic resin does not degrade or decompose during thepreparation of this paving material by the heat-mixing method, if theconditions allow mixing to be completed in a short period of time.Instead of decomposing or being degraded, a portion of the syntheticresin particles either deform of fuse to increase the adhesivenessbetween the synthetic particles and the binder to produce an excellentpaving material from which the binder cannot be easily stripped. It hasalso been discovered that even when mixing is conducted at ambienttemperature, there is unexpected adhesiveness between the syntheticresin particles and the binder, if the resin particles have at least onebroken or roughened surface.

In order to produce a strong paving material, it is necessary to useaggregate having both great strength and great adhesiveness to thebinder used, such as gravel, sand, and crushed stone. However, prior tothe present invention, it was unexpected that thermoplastic syntheticresin particles could have sutficient strength to replace some or all ofthe conventional aggregate, have sufficient adhesion between thesynthetic resin particles and the binder to be suitable for use as apaving material, and have sufiicient heat resistance to withstand theheating in the heat-mixing method.

The thermoplastic synthetic resin particles used in the composition ofthe present invention are solids having a maximum lengthwise diameter ofabout 1-20 mm., and preferably 1-13 mm. Suitable particles includepellets produced by molding thermo-plastic resins such as vinyl chlorideresins, polyethylene, polypropylene, polystyrene,acrylonitrile-butadiene-styrene and methacrylic resins; or fragmentsobtained by crushing shaped articles made from these resins, such assheets, pipes, containers, as well as mechanical parts, electrical partsand miscellaneous good, in a suitable crusher such as a jaw crusher orimpeller breaker.

If synthetic resin powders are used in the aggregate composition insteadof a particulate material such as pellets or fragments, these powderysynthetic resins either melt or decompose during the heat-mixing processof making the paving material and the paving material is completelyuseless.

The amount of aggregate replaced depends on the composition of theaggregate and is usually an amount from 3 to 50% by weight of the totalaggregate weight when the aggregate replaced has a large particle size;i.e., crushed stone and gravel. The replacement rate for such largeaggregate is from to by weight when the composition is to be used forpaving roads for automotive traffic necessitating a high safetyrequirement. When aggregate having a smaller particle size; i.e., sand,is to be replaced, from 3 to 75% by weight of the total aggregate weightcan be usually replaced, while if the. safety requirements are high, therate of replacement should be up to a maximum of by weight. At amountsof thermoplastic resin below the minimum; i.e., 3% there is virtually noimprovement of the physical properties of the aggregate composition andin fact, the physical properties are often less desirable thancompositions containing no plastic.

When colored synthetic resin particles are used in the aggregatecomposition, a colored paving composition is obtained, especially when apetroleum resin is used as the binder, since petroleum resin produces alight-colored paving composition. This embodiment of the composition ofthe present invention comprises a petroleum resin and aggregate havingup to by weight, and preferably up to 50% by weight replaced byparticles of colored synthetic resin. In order to produce the color whena darker colored bituminous material is used as the binder, the surfaceof the compacted mixture must be polished by a grinder or the like toexpose the colored synthetic resin particles incorporated in thesurfacing materal.

Colored pavements have been used in the past for such purposes asbeautification; i.e., pedestrian walks, parking areas, parks andshop-lined streets; tratfic safety; i.e., as crosswalks, to indicatehigh accident areas, mark the inside of tunnels, etc., or mark thesurface of the roadway, junctions, bus stops, etc. Prior art coloredpaving composition consists of a naturally colored aggregate, abituminous material or a petroleum resin and a silica such as sand orlimestone having a whitish color, reddish brown colcothar, aluminumparticles, vitreous aggregate, fragments of colored china, etc.Colcothar is primarily used because it is inexpensive and does notbecome discolored and also the color harmonizes with the green lawns ofparks or grass planted along the roads. The colored paving compositionof the present invention may be produced both when a portion ofconventional aggregate is replaced with colored synthetic resinparticles, and also when a portion or all of the conventional coloredaggregate is replaced with colored synthetic resin particles.

A typical method of preparing the composition of the present inventioncomprises heating crushed stone or gravel, sand and filler, such aslimestone filler, to a temperature of from 170 to 200 C. in a dryer,measuring these materials and charging the same in a mixer and mixingthese materials in a dry state. A pre-determined amount of syntheticresin in pellet or fragment form is charged to the mixer during this drymixing period, either at ambient temperatures or after pre-heating withan added dry mixing period of from 5 to 10 seconds. After completion ofthe dry mixing, a pre-determined amount of a bituminous material heatedto 140-160 C. or a petroleum resin heated to -150" C. is sprayed ontothe aggregate and synthetic resin pellets or fragments, and the mixtureis wet-mixed until the agregates and the synthetic resin pellets orfragments are completely coated with the binder, usually within 30-60seconds. After completion of these mixing operations, the mixture isdischarged and the spreading and compacting of this paving compositionare carried out in the customary manner.

The composition of the present invention can be used not only for roadpaving purposes, but also for the manufacturing of blocks such as tilesand molded articles like terrazzo.

When mold articles like terrazzo are produced, the aggregate, syntheticresin particles and binder mixture are placed in a mold and compactedthoroughly by a hot press or similar apparatus. After the compactedmixture is cooled, it is removed from the mold and its surface ispolished by a grinder or the like or shaved off with a lathe or thelike, to expose the incorporated synthetic resin particles, therebyproducing molded articles like terrazzo.

While any synthetic resin particles within the abovenoted classes ofresins and particle sizes may be used, it is especially preferred to usecolored and nontransparent resin particles.

The composition of the present invention will now be illustrated by thefollowing non-limiting examples wherein all parts and percentages are byweight and temperatures in degrees Centigrade.

EXAMPLE 1 The compositions as shown in Table I are formed by heating thepremeasured aggregate; i.e., crushed atone, coarse sand, fine sand andlimestone filler to 170-190 C., adding the predetermined amount ofasphalt (penetration grade 80-100) which was heated to ISO-160 C. Thesynthetic resins were then added except in samples I and V. Theaggregate and asphalt were co-mingled until the latter thoroughly coatedthe former, usually a period of 2 minutes. This mixture was then placedin a mold and, when the temperature fell to -14S C., was compacted bytamping.

The Marshall stability test of the mixture consisting of aggregate,i.e., crushed stone, sand, limestone filler and synthetic resinfragments and asphalt was carried out in accordance with ASTM D1559-62T. The water resistance was tested by means of the Marshall waterimmersion test, i.e., immersion for 24 hours at 60 C. To check thedeformation and deterioration caused by heat, the samples,

compacted by tamping, were placed in a 150 C. oven for 2 hours, thencooled to room temperature, and thereafter submitted to the Marshallstability test, noted as the heat resistance test in Table 1.

The composition of the samples and the test results demonstrate astability superior to those not including the synthetic resin fragments.

TABLE 3.P ROPE RTIES that the paving compositions of the presentinvention thereof are shown in Table 1. It can be seen that the com- 5Rate of positions obtained by compounding the components in asphalt Flowaccordance with the present invention demonstrate un- 2722?; g 33 1? gexpectedly excellent stability and that the water resistance p 2. 328 3.24 13. 63 770 10 and heat reslstance are also very good. 10 L950 5.34 A21,840 76 Also, when powdered polyvinyl chloride, powdered 1.465 8.448.58 1,967 103 polystyrene, and powdered acrylonitrile-butadiene-styrene2'? gig copolymer were incorporated in the composition instead 1. 9514.76 11:48 a; 000 of the synthetic resin fragments, the former synthetic339 {Z 1. 529 4. 44 8.95 3,000 resms melted and decomposed during themixing operation. 15 Test samples were not broken at 3,000 kg.

TABLE 1 Standard Marshall Marshall water Heat resistance test immersiontest test Flow Flow Flow Density Stability (l./100 Stabilit (l./100Stability (l./100 Composition (gJcmfl) (kg.) cm.) (kg.) cm. (kg.) cm.)

Sample I.-Crushed stone (5-2.5 mm.) wt. pt.; Sand (2.5-1.2 mm.) 30 wt.pt.; sand (less than 1.2 mm.) 30 wt. pt.; lime stone filler 10 wt. pt.;asphalt 7 wt. pt- 2. 285 449 27 380 23 Sample II.-orushed stone (5-2.5mm.) 30 wt. pt.; ABS fragments (2.5-1.2 mm.) 30 wt. pt.; sand (less than1.2 mm.) 30 wt. pt.; lime stone filler 10 wt. pt.; asphalt 7 wt. pt 1.636 1, 788 47 1, 669 38 Sample III.-Crushed stone (5-2.5 mm.) 30 wt.pt.; ABS" fragments (2.5-1.2 mm.) 15 wt. pt.; sand (2.5-1.2 mm.) 15 wt.pt.; sand (less than 1.2 mm.) 30 wt. pt.; lime stone filler 10 wt. pt.;asphalt 7 wt. pt 1. 904 1. 431 41 Sample IV.-Crushed stone (52.5 mm.) 30wt. pt.; PS fragments (2.5-

1.2 mm.) 15 wt. pt.; sand (2.5-1.2 mm.) 15 wt. pt.; sand (less than 1.2mm.) 30 wt. pt.; lime stone filler 10 wt. pt.; asphalt 7 wt. pt 1. 9171, 924 48 1, 883 40 2, 012 27 Sample V.Crushed stone (10-5 mm.) 30 wt.pt.; crushed stone (5-2.5

nun.) 20 wt. pt.; sand (less than 1.2 mm.) 40 wt. pt.; lime stone filler10 wt. pt.; asphalt 5.7 Wt. pt 2. 326 745 33 692 35 Sample VI.-Crushedstone (10-5 mm.) 30 wt. pt.; crushed stone (5-2.5 mm.) 10 wt. pt.; PVCfragments 45-25 mm.) 10 wt. pt.; sand (less than 1.2 mm.) wt. pt.; limestone filler 10 wt. pt.; asphalt 5.7 wt. pt 2. 139 843 37 756 40 832 34Sample VII.-Crushed stone (10-5 mm.) 30 wt. pt.; crushed stone (5-2.5mm.) 10 wt. pt.; PE fragments (5-2.5 mm.) 10 wt. pt.; sand (less than1.2 mm.) 40 wt. pt.; lime stone filler 10 wt. pt.; asphalt 5.7 wt. pt 1.997 856 36 763 41 Sample VIIL-Crushed stone (10-5 mm.) 30 wt pt.; PPfragments (5- 2.5 mm.) 20 wt. pt.; sand (less than 1.2 mm.) 40 wt. pt.;lime stone filler 10 wt. pt.; asphalt 5.7 wt. pt 1.725 1,384 45 1, 125

*- ABS=Acrylo nitrile, butadiene, styrene copolymer. d PE=Polyethylene.b PS=Polystyrene. Q PP=Polypropylene. PVC=Vinyl chloride resin.

EXAMPLE 2 EXAMPLE 3 45 The compositions as set forth 111 Table 2 arecom- The aggregates having the particle sizes as shown in pounded usingthe procedure of Example 1, except the Table 4 were used in accordancewith the composition asphalt was heated to 145-160 C. The polypropylenegiven in Table 5. The crushed stone, sand and limestone fragments wereproduced by crushing a polypropylene filler were first heated at 170-190C., and mixed with beer container. The aggregate and the polypropylenepar- 50 asphalt, penetration grade 80-100, specific gravity 1.025,tlcles were thoroughly mlxed wlth the asphalt r about which had beenheated at 140-160 c. The vinyl chloride 2 mmutes unhl the aggregates andP yp py fragvinyl acetate copolymer fragments, which were at room mentsare coated with asphalt. When a relatively large temperature, were hadded, and this mixture was f of P yp p was added, e 3040% PY mingledfor about 2 minutes. This mixture was compacted l welght of the totaltefnperatElrF of the P by tamping at three different temperatures, asshown in ture fell to about 130 C., necessltatlng additional heating.Table 6' The physical properties of these compositions The mixture wascompacted by tamping at a temperature h are s own in Table 6. of 145-150C.

TABLE 2 Sample Composition (wt. parts) I II III IV V VI VII VIII TABLE 4Crushed stone and coarse sand: Vinyl Crushed stone (10-5 mm.). 40 30 1040 40 40 20 40 chloride. Crushed stone (5-2.5 vinyl m 20 10 acetate LimeSand 10 10 10 10 Crushed copolymer stone Polypropylene fragmentsAggregate stone fragments Sand filler mm F. 2- 1' 2 t 4 10 n 10Pgtgllles passing through sieve aggrega e5? 20 t 100 Sand (less than 1.2mm.)- 25 25 25 25 25 25 25 25 13 $1 3;33, 9&6 100 Limestone filler 5 5 55 5 5 5 5 5 t 11,3 99, Asphalt 6 6 6 6 6 6 6 6 2.5 mm., percent 1.4 45.

mm., percent..- 1. 3 These samples are tested as in Example 1 and there- 3 1 P8555351 j c be 5 n 1 0.074 mm., percent-.- .7 8 .3 sults areshown m Table 3 It an ee from Tab e 3 Apparent Specific gravity 2 653 1300 2 577 mm 7 TABLE 5 Weight parts Crushed stone 24 13 Vinyl chlorideresin Sand Lime stone filler Asphalt TABLE 6.-PROPERTIES Rate of TampingThe samples as shown in Table 7, except for samples III and IV, wereprepared in accordance with the procedure of Example 1, except that theaggregate was heated to 160180 C. and mixed with a petroleum resinheated to 135145 C. These samples were molded at 130-140 C. withcompacting.

Samples III and IV were prepared by heating the crushed stone, sand,limestone filler and synthetic resin fragments and pellets to 120140 C.The petroleum resin heated to 135-145 C. was added to this mixture ofaggregate and pellets, and mixed until the crushed stone, sand,limestone filler and synthetic resin fragments and pellets werecompletely coated with the petroleum resin. This mixture was placed in amold at 130140 C. and compacted by tamping.

The stability of the mixture of the aggregates and pellets, i.e.,crushed stone, sand, limestone filler and synthetic resin fragments andpellets, and the petroleum resin was tested using the Marshall stabilitytest in accordance with ASTM D 1559-62T, with the test results shown inTable 7.

The mixture was then placed in a mold and compacted first by tamping itdownward 50 times and then, after turning the mixture upside down, bytamping it downward 50 times, at ISO-160 C. The samples were removedfrom the molds after 24 hours and the Marshall stability of each samplewas determined in accordance with ASTM D 1559-62T with the test resultsshown in Table 9.

TABLE 9 Polypropylene fragments Flow (wt. Density Void Stability (1./100Sample parts) (g./cm.) (percent) (kg) cm.)

Table 9 shows that the compositions of samples III, IV and V, having atleast 3% by weight of the synthetic thermoplastic resin particles basedon the total aggregate, have a remarkable improvement in Marshallstability.

What is claimed is:

1. In a composition useful as a paving material comprising in admixtureaggregate and a binder selected from the group consisting of abituminous material and a petroleum resin, the improvement wherein from375% by TABLE 7 Theoretical Flow Density density Voids Stability (l./100Composition (g./cm. (gJomfl) (percent) (kg.) cm.) Sample I.Crushed stone(5-2.5 mm.) 30 wt. pt.; sand (2.5-1.2 mm.) 30 wt. pt.; sand (1.2-

0.6 mm.) 10.7 wt. pt.; sand (less than 0.6 mm.) 19.3 wt. pt.; lime stonefiller 10 wt. pt.; petroleum resin 7.0 wt. pt 2. 272 2. 420 6.1 451 27Sample I1.Crusl1cd stone (52.5 mm.) wt. pt.; PVC fragments (5-2.5 mm.)15 wt. pt.; sand (2.6-1.2 mm.) 30 wt. pt.; sand (1.2-0.6 mm.) 10.7 wt.pt.; sand (less than 0.6 mm.) 19.3 wt. pt.; lime stone filler 10 wt.pt.; petroleum resin 7 .0 wt. pt 1. 929 2.134 9. 6 657 38 Sample IIl.Crushed stone (5-2.5 mm.) 10 Wt. pt.; PVC fragments (52.5 mm.) Wt. pt.;

sand (2.5-1.2 mm.) 10 wt. pt.; PVC fragments (2.5-1.2 mm.) 20 wt. pt.;PVC fragments (1.2-0.6 mm.) 10.7 wt. pt.; sand (less than 0.6 mm.) 19.3wt. pt.; lime stone filler 10 Wt. pt.; petroleum resin 7.0 wt. pt 1.465 1. 664. 11. 8 1, 013 74 Sample 1V.--PVC fragments (5-2.5 mm.) wt.pt.; PVC fragments (2.5-1.2 mm.) 30 wt. pt.; PVC fragments (1.2-0.6 mm.)10.7 wt. pt.; sand (less than 0.6 mm.) 19.3 wt. pt.; lime stone filler10 wt. pt.; petroleum resin 7.0 wt. pt 1. 287 1. 481 13. 1 1, 267 69Sample V.Crushed stone (5-2.5 mm.) 15 wt. pt.; phenol resin fragments(5-2.5 mm.) 15 wt. pt.; sand (2.5-1.2 mm.) 30 Wt. pt.; sand (1.2-0.6mm.) 10.7 wt. pt.; sand (less than 0.6 mm.) 19.3 wt. pt.; lime stonetiller 10 wt. pt.; petroleum resin 7 .0 wt. pt 2. 002 2. 165 7. 5 402 26Sample VI.Crushed stone (5-2.5 mm.) 15 wt. pt.; ABS pellets (5-2.5 mm.)15 wt. pt.; sand (2.5-1.2 mm.) 10.7 wt. pt.; sand (less than 0.6 mm.)19.3 wt. pt., ime stone filler 10 Wt. pt.; petroleum resin 7 .0 Wt.pt 1. 656 1. 729 4. 2 1, 396 48 EXAMPLE 5 The compositions as shown inTable 8 were prepared by heating the mixture of crushed stone, sand andlimestone filler to about 200 C. in an air-oven, followed by mixing withasphalt so that the aggregate was coated with the asphalt. Thepolypropylene fragments produced by crushing a thick-shelled beercontainer were then added to the mixture and mixed until the fragmentswere substantially coated with the asphalt.

TABLE 8 Sample Composition (in wt. pts.) I II III IV V Crushed stone(13-5 mm.) 35 35 35 35 Crushed stone (52.5 mm.) 20 18 17 15 12Polypropylene fragments (5-2.5 mm.).. 0 2 3 5 8 Sand (less than 2.5 mm.)40 40 40 40 Limestone filler 5 5 5 5 5 6 6 6 6 6 Asphalt material isasphalt.

5. The composition of claim 1 wherein the bituminous material is tar.

6. The composition of claim 1 wherein the synthetic thermoplastic resinparticles are colored.

7.-The composition of claim 1 wherein the synthetic thermoplastic resinparticles have a maximum lengthwise diameter of 1-13 mm.

References Cited UNITED STATES PATENTS Buchholtz et a1. 260-37 N Sapp26037 N McConnaughay 106281 R Verdol 26028.5 AS 10 MORRIS LIEBMAN,Primary Examiner S. L. FOX, Assistant Examiner US. Cl. X.R.

26028.5 A, 28.5 B, 28.5 D, 28.5 AS, 41 R (SEAL) UNITED STATES PATENTOFFICE v CERTIFICATE OF CORRECTION Patent No. 3,849,355 Dated November19, 1974 Ihventofls) 1 Kaoru YAMAGUCHI ET AL I It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 8, line 2 of Claim 2: cancel "fragment sfi Q Column 8, line 2 ofClaim 3: after "are" insert fragments Signed and sealed this 14th dayofJanuafy 1975.

Agtest: I

14:00? rmcnssofi JR. c. MARSHALL DANN Attesting Officer Commissionerof-Patents

1. IN A COMPOSITION USEFUL AS A PAVING MATERIAL COMPRISING IN ADMIXTUREAGGREGATE AND A BINDER SELECTED FROM THE GROUP CONSISTING OF ABITUMINOUS MATERIAL AND APETROLEUM RESIN, THE IMPROVEMENT WHEREIN FROM3-75% BY WEIGHT OF SAID AGGREGATE IS REPLACED WITH SOLID SYNTHETICTHERMOPLASTIC RESIN PARTICLES SELECTED FROM THE GROUP CONSISTING OFVINCYL CHLORIDE RESINS, POLYETHYLENE, POLYPROPYL ENE, POLYSTYRENE,ACRYLONITRILE-BUTADIENE-STYRENE AND METHACRYLIC RESINS IN THE FORM OFPELLETS OR FRAGMENTS HAVING A MAXIMUM LENGTHWISE DIAMETER OF ABOUT 1-220MM. IN SAID ADMIXTURE.